Is my custom field added in page struct guaranteed zero when a page is allocated ?
hi, I add a u64 field in struct page to record corresponding disk sector postion. I will change and read this field when dealing with page cache staff. I want it stays zero unless my code change its value. Will the kernel 's allocating code guarantee that the field is zero when the page is allocated? or Need I add some code to the allocating routine to explicitly fill the field with zero? Regard， Lingyu Zhu
On Mar 14, 2014 9:26 PM, "朱" <zly.king@163.com> wrote:
hi, I add a u64 field in struct page to record corresponding disk sector
postion. I will change and read this field when dealing with page cache staff. As you already have modified page struct, how about modifying prep_new_page as well. Put a zero in that field after the page refcount is set. I think that way it'll remain.hidden instead of your specific code zeroing it everytime you need it.
I want it stays zero unless my code change its value. Will the kernel 's allocating code guarantee that the field is zero when the page is allocated? or Need I add some code to the allocating routine to explicitly fill the field with zero?
Regard， Lingyu Zhu
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